The present invention is in automatic door operators such as used in garage doors. Such automatic door operators typically employ a motor to move the door between an opened and a closed position in response to control signals. A wall mounted push button and a portable radio frequency transmitter are generally provided to generate these control signals.
It has been known for many years that such automatic garage door operators need some form of obstruction detection. Obstruction detection prevents personal injury or property damage caused by the controlled door closing on something. Obstruction detection also prevents damage to the door and the various driving components that would result from operation against an obstacle.